This section provides background information related to the present disclosure, which is not necessarily prior art.
A food waste disposer of the type that is disposed underneath a sink and is mounted to a drain opening of the sink typically includes a food conveying section, a motor section and a grind section. The grind section is disposed between the food conveying section and the motor section. The food conveying section conveys food waste and water to the grind section. The grind section receives and grinds the food waste and the ground food waste is discharged through a discharge opening to a tailpipe.
The grind section typically includes a grind mechanism with a rotating shredder plate assembly and a stationary grind ring. The shredder plate assembly is connected to a shaft of an electric motor of the motor section and includes a shredder plate with one or more lugs, typically one or more pairs of lugs. The lugs may include fixed lugs that are fixed to the shredder plate, rotatable lugs (also called swivel lugs) that are rotatably fastened to the shredder plate and are free to rotate thereon, or both. The shredder plate is rotated relative to the grind ring via the electric motor. The grind ring is typically mounted in a housing and includes multiple spaced teeth.
The operational noise of a food waste disposer is a combination of grinding noise, water spectrum, and motor noise. Grinding noise arises from the interaction of the food waste with the grind mechanism components and the container body. It is characterized by random impulsive noise events from impacts and it changes over time as the food waste is broken up and discharged to the drain line. The water spectrum noise arises from the running water exiting the faucet, impinging upon the sink, and being moved about within the food waste disposer. Motor noise is typically a steady state noise with a consistent frequency content but it can vary from unit to unit as the characteristics of motor noise are highly affected by bearing alignment and variations in rotor/stator air gap.
Passive noise control is currently used to reduce the operational noise levels of food waste disposers. Passive methods include the use of (1) absorbent and barrier materials to absorb and/or block sound energy traveling through the container body or motor housing, (2) vibration isolation mounts at the sink and plumbing interfaces to reduce structure borne noise from the sink and plumbing, and (3) use of baffling at the throat opening to attenuate air borne noise from the grind chamber. Passive methods have been effective in reducing the noise levels perceived by the user during operation of the food waste disposer. However, there are practical constraints to how much noise reduction can be achieved by these means, especially in frequency ranges 1 kHz and lower.
FIG. 1 depicts a prior art food waste disposer 100 which is similar to the prior art food waste disposer described in U.S. Pat. No. 7,360,729 the entire disclosure of which is incorporated herein by reference. The disposer includes an upper food conveying section 102, a central grinding section 104 and a motor section 106, which may include a variable speed motor. It should be understood that motor section 106 could also include a fixed speed motor, such as an induction motor. The grinding section 104 is disposed between the food conveying section 102 and the motor section 106.
The food conveying section 102 conveys the food waste to the grinding section 104. The food conveying section 102 includes an inlet housing 108 and a conveying housing 110. The inlet housing 108 has an inlet 109 at the upper end of the food waste disposer 100 for receiving food waste and water. Inlet 109 is surrounded by a gasket 111. The inlet housing 108 is attached to the conveying housing 110, such as by an antivibration mount 113.
The conveying housing 110 has an opening 142 to receive a dishwasher inlet 144. The dishwasher inlet is used to pass water from a dishwasher (not shown). The inlet housing 108 and conveying housing 110 may be made of metal or molded plastic. Alternatively, inlet housing 108 and conveying housing 110 may be one unitary piece.
The grinding section 104 includes a housing 112 surrounding a grinding mechanism 114 having a rotating shredder plate assembly 116 and a stationary grind ring 118. Housing 112 is formed as a clamp ring and clamps conveying housing 110 to an upper end bell 136 of motor section 106. Stationary grind ring 118, which includes a plurality of spaced teeth 120 (only two of which are indicated by reference number 120 in FIG. 1), may be received in an adaptor ring 122 disposed between housing 112 and stationary grind ring 118. A gasket 123 is disposed between adaptor ring 122 and an upper portion 125 of housing 112. A bottom flange 127 of conveying housing 110 is received in gasket 123 and gasket 123 seals conveying housing 110 to adaptor ring 122.
The rotating shredder plate assembly 116 may include a rotating shredder plate 124 mounted to a rotatable shaft 126 of a motor 128 of motor section 106, such as by a bolt 130. Motor 128 also includes a rotor 129 to which rotatable shaft 126 is affixed and a stator 131. A plurality of fixed lugs 132 (only one of which is shown in FIG. 1) are mounted on rotating shredder plate 124 as are a plurality of swivel lugs 134 (only one of which is shown in FIG. 1). It should be understood that in this regard, rotating shredder plate assembly 116 could include only fixed lugs 132 or only swivel lugs 134.
An upper end bell 136 is disposed beneath a bottom of rotating shredder plate 124. Upper end bell 136 includes a discharge chamber 140 having a discharge outlet 141 for coupling to a tailpipe or drainpipe (not shown).
In an aspect, food waste disposer 100 may include a trim shell 146 that surrounds food conveying section 102, grinding section 104 and motor section 106. A layer of sound insulation 148 may be disposed between trim shell 146 and conveying housing 110 of food conveying section 102 and housing 112 of grinding section 104.
Food waste disposers such as food waste disposer 100 are often generally installed to a sink in a two-step procedure using a mounting assembly 200 of the type described in U.S. Pat. No. 9,139,990. With reference to FIG. 2, first, a sink flange assembly 202, consisting of a sink flange 204, sink gasket 206, back-up flange 208, upper mounting flange 210, bolts 212, and retaining ring 214 are installed to the sink (not shown). Second, a disposer assembly consisting of a disposer such as disposer 100 (FIG. 1), a mounting gasket 216 (which is mounting gasket 111 in FIG. 1), and a lower mounting flange 218 are attached to the sink flange assembly. Lower mounting flange 218 is placed around inlet housing 108 of food conveying section 102 so that it is beneath inlet 109. Mounting gasket 216 is then placed around inlet 109. Inlet housing 108 of food conveying section 102 includes circumferential lip 188 extending around the circumference of inlet 109. Lip 188 is received in a corresponding recess (not shown) in mounting gasket 216 to secure mounting gasket 216 to food waste disposer at inlet 109. The attachment method, as described in U.S. Pat. No. 9,139,990, consists of engaging the mounting tabs 220 of the lower mounting flange 218 with the inclined mounting ramps 222 of the upper mounting flange 210 then rotating the lower mounting flange 218 until secure. The typical installation method involves raising the disposer 100 and mounting components to the sink flange assembly 202 with one hand then with the other hand lifting the lower mounting flange 218 and rotating to engage its mounting tabs 220 to the mounting ramps 222 of upper mounting flange 210. Rotating the lower mounting flange 218 brings it and upper mounting flange 210 securely together, compressing the mounting gasket 216 therebetween, and secures the disposer 100 to the sink flange assembly 202.
In the operation of the food waste disposer 100, the food waste delivered by the food conveying section 102 to the grinding section 104 is forced by lugs 132, 134 of the rotating shredder plate assembly 116 against teeth 120 of the stationary grind ring 118. The sharp edges of the teeth 120 grind or comminute the food waste into particulate matter that combines with water, such as water that entered the food waste disposer through inlet 109, to form a slurry that drops into discharge chamber 140. This slurry is then discharged through the discharge outlet 141 into the tailpipe or drainpipe (not shown).